It is well known to provide impact absorbing systems, often called “crash attenuators” or “crash cushions” in association with guardrails. The guardrails may be disposed along roadways or utilized adjacent to rigid structures such as pillars, bridge abutments, lighting poles and the like for the purpose of absorbing vehicle impact energy and minimizing the effects of impact on the vehicle, the vehicle occupants and any ancillary structure being protected.
There are many forms and types of energy absorbing barriers. The following patent documents are believed to be representative of a variety of crash attenuator systems including patents disclosing such systems on or in connection with guardrails employing a plurality of overlapping side panels which are relatively movable and telescope in the event of a vehicle collision with an end of the structure:
U.S. Pat. No. 4,838,523, issued Jun. 13, 1989, U.S. Pat. No. 4,655,434, issued Apr. 7, 1987, U.S. Pat. No. 4,739,971, issued Apr. 26, 1988, U.S. Pat. No. 7,926,790, issued Apr. 19, 2011, U.S. Pat. No. 8,360,400, issued Jan. 29, 2013, U.S. Pat. No. 8,424,849, issued Apr. 23, 2013, U.S. Pat. No. 4,330,106, issued May 18, 1982, U.S. Pat. No. 7,086,805, issued Aug. 8, 2006, U.S. Pat. No. 5,851,005, issued Dec. 22, 1998, U.S. Pat. No. 6,811,144, issued Nov. 2, 2004, U.S. Pat. No. 9,051,698, issued Jun. 9, 2015, and Patent Application Publication No. US 2013/0140510, published Jun. 6, 2013.
As will be seen below, the present invention incorporates sliders of a distinctive character in operative association with overlapping rail panels of a crash absorbing guardrail panel assembly.
The use of sliders per se are known generally in the crash absorbing guardrail art, but the structural combination and manner of operation of the present invention differ considerably from such known impact slider arrangements.
U.S. Pat. No. 7,926,790, issued Apr. 19, 2011, shows an impact slider assembly for a guardrail including a slider connected to a first rail and a slider substantially surrounding the first rail, so that in use, the slider gathers and retains the first and any subsequent rails which telescopically overlap with each other during an impact.
U.S. Pat. No. 8,424,849, issued Apr. 23, 2003, discloses an impact slider assembly for a guardrail which includes: a slider mechanism attached to a first rail and a second rail which substantially conforms with a rail profile; and an integral means for attachment to the first rail, wherein the slider mechanism gathers telescoping rails while substantially maintaining the strength of the rails in a fully re-directing manner.